I’m really lucky to have a father who teaches exercise science and physiology at the college level. I’ve never had a triathlon coach, but growing up with my dad, I have a decent foundation in exercise physiology and training concepts. Over the years, I’ve further built upon this through reading the books, blogs, and tweets of the best in the business (notably Joe Friel and Gordo Byrne among many others). Anyway, in addition to imparting his knowledge, my dad also has access to some cool equipment, which he utilizes in his classes. As an age grouper, I’ve had the rare opportunity to have a VO2 Max Test performed… twice! The first was in 2008, just four weeks after my first Ironman. The second time was this past November, but about 2 months into the off-season.

My dad, the quintessential professor, setting up the equipment for the test.

But before we get into the test itself, I’ll take a minute to describe what VO2 Max tests measure and a bit about how they work. Most coaches and exercise scientists will agree that for an endurance athlete to progress, there are really three components to improve, aerobic capacity, lactate threshold, and economy (or efficiency). Also referred to as VO2 Max, aerobic capacity is a measure of your ability to use oxygen to produce the energy needed to pedal your bicycle or continue swimming/running at a certain pace. In triathlons, the fastest athletes in the race tend to have the highest VO2 Max and this is generally the best predictor of speed (better than lactate threshold and efficiency – although over longer time and distance, efficiency can have a significant impact). The name VO2 Max comes from the main components of the test, V – volume per minute, O2 – oxygen, Max – maximum. It is also called maximal oxygen consumption or maximal aerobic capacity. It tests the maximum rate of oxygen consumption as measured during exercise in which the intensity is progressively increased, usually on a treadmill or cycle ergometer (a fancy exercise bike). VO2 max is expressed either as an absolute rate, usually liters of oxygen per minute (L/min) or as a relative rate, such as milliliters of oxygen per kilogram of body mass per minute (ml/kg/min). In my case we’ll perform the test on a cycle ergometer and express measurements in (ml/kg/min,) which takes body weight into account. Expressing oxygen consumption in absolute terms has some advantages. For instance, if one is interested in caloric expenditure, one can easily utilize the relationship, 1 liter of O2 consumed ≈ 5 Kcal expended. And, if significant weight change is expected, using the absolute term avoids the misconception that oxygen consumption changed when in fact only body weight changed. Expressing oxygen consumption in relative terms, i.e., relative to one’s body weight, has the advantage of being able to compare one’s results with those of others regardless of their body weight. And thus, ‘norms’ may be used to judge one’s fitness level.

The weekend before Thanksgiving, my brother and I were home to visit our parents. We went with my dad to work and after he taught his morning classes, we set up in the lab. I began warming up on the bike while my dad calibrated the equipment and Evan assisted with setup and took some pictures. We devised the test protocol based on my anticipated fitness level. As mentioned earlier, the test becomes incrementally more difficult, so you have to choose how quickly to raise the pace (treadmill) or power output (cycle ergometer) in terms of interval duration and increase in power output. For me, we decided to do 2 minutes at each stage, initially increasing by 35 watt (w) increments until I reached 175 watts; then we increase by 25 watts for the remainder of the test – until I fail to maintain the required power output. This is the point at which you can’t pedal anymore and quit from exhaustion, sounds fun huh?

My dad, the quintessential professor, setting up the equipment for the test.

How many Bossos does it take to get the seat height right?

There is quite a bit of equipment to calibrate beforehand

The test is a measure of oxygen consumption, so you must track the volume and composition air inhaled and exhaled during the test. As you can see in the photos, the subject must have a mask strapped to their face to ensure all airflow is measured accurately. It’s not exactly awesome to be turning yourself inside out on a bicycle with a mask on your face… but there are worse things in life. Meanwhile, the equipment is capturing heart rate, power output, volume and composition of expired air (ventilation) and more.

Evan “helped” me get set up

We can never be too serious

So basically my dad controls the cycle ergometer, which adjusts resistance to maintain the selected power level in watts (w). We started at 35w and I relatively easily moved from 35w to 70w to 105w. At each interval we were measuring my heart rate and the system was capturing my oxygen consumption and a few other metrics (most notably, volume of expired air – also called ventilation). At 140w and eight minutes into the test, things start to get interesting and the move to 175w felt a little more difficult than I expected. In the middle of triathlon season, I was averaging about 200 watts for over an hour during the bike leg of a triathlon. But in this case, I really hadn’t been doing any serious training for two months. Anyway, the test had to go on, now escalating in 25w increments. I powered through 200w, 225w, and 250w with some discomfort, then started really suffering at 275w and 300w before failing as we increased the resistance to 325w. See the video below for an idea how this all looks in practice.

Progressing through the stages with the Professor working the protocol.

Since this has already been quite a long and technical post, we’ll stop there. Part 2 will reveal my VO2 Max and discuss how this test helps us become better athletes.